manifest

#!/bin/bash

function usage
{
    echo "usage manifest --key <com.mykey.blah> [--value <VALUE>] [--file <FILE>]"
}

filename=/opt/manifest.json
key="."
value=""
jq_command="jq -M"

while [ "$1" != "" ]; do
    case $1 in
        -f | --file )           shift
                                filename=$1
                                ;;
        -k | --key )            shift
                                key=$1
                                ;;
        -v | --value )          shift
                                value=$1
                                ;;
        -h | --help )           usage
                                exit
                                ;;
        * )                     usage
                                exit 1
    esac
    shift
done

if [ ! -f $filename ]; then
    echo "{}" > $filename
fi

if [ -z "$value" ]; then
    #This is a query
    $jq_command $key $filename
else
    #This is an assignment
    out=`${jq_command} "$key=\"$value\"" $filename`
    echo $out > $filename
fi